Should I put the FI back on with a big bore kit and cam? |
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Should I put the FI back on with a big bore kit and cam? |
Matty900 |
Mar 27 2016, 10:42 PM
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#1
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Senior Member Group: Members Posts: 1,269 Joined: 21-February 15 From: Oregon Member No.: 18,454 Region Association: Pacific Northwest |
I have a 72 with a 1.7 that has a 1911 big bore kit and cam. Ithe has dollorto carbs on it. Should I go back to fuel injection? If so how do I do it?
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jcd914 |
Mar 27 2016, 11:00 PM
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#2
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Advanced Member Group: Members Posts: 2,081 Joined: 7-February 08 From: Sacramento, CA Member No.: 8,684 Region Association: Northern California |
Do you know what cam it has in it?
D-jet does not like much in the way of cam above stock. L-jet will tolerate a bit more cam but still not a lot. Some aftermarket FI can be made to run with almost anything with enough time and know how. Jim |
porschefile2010 |
Mar 28 2016, 02:25 AM
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#3
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Member Group: Members Posts: 228 Joined: 26-May 11 From: Whangaparaoa, New Zealand Member No.: 13,118 Region Association: Australia and New Zealand |
You just need to be sure the 1.7 FI can get enough fuel through so that it doesn't run too lean or you will blow holes through the heads. This happened to me with a 2.0 which had been made ( unbeknown to me at the time) into a 2.3 but left with with the original 2.0 FI. Blew the heads. Unless you are sure safer to go to carbs which is unfortunate cos the FI is pretty reliable.. Good luck with the 1911.
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r_towle |
Mar 28 2016, 12:41 PM
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#4
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
the "big bore" is not an issue.
Both djet and ljet can support up to 2.4 liters (as far as I have tested) What camshaft did you put in? Specific number and manufacturer. Rich |
brant |
Mar 28 2016, 01:09 PM
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#5
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914 Wizard Group: Members Posts: 11,625 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
If it's a cam with lift that would upset the vacuum signal for the manifold pressure signal then factory fuel injection will not work well
So the cam specs are needed to answer your question Or mega squirt |
Matty900 |
Mar 28 2016, 01:10 PM
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#6
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Senior Member Group: Members Posts: 1,269 Joined: 21-February 15 From: Oregon Member No.: 18,454 Region Association: Pacific Northwest |
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Matty900 |
Mar 28 2016, 02:11 PM
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#7
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Senior Member Group: Members Posts: 1,269 Joined: 21-February 15 From: Oregon Member No.: 18,454 Region Association: Pacific Northwest |
the "big bore" is not an issue. Both djet and ljet can support up to 2.4 liters (as far as I have tested) What camshaft did you put in? Specific number and manufacturer. Rich Just heard back from previous owner, It still has the original cam, all he did was a big bore slip in barrel no block mods completely went through heads guides and seals and check for warp and cracks. Just head work. It was $460 back in 2005 or 2006 and has only had between 2,000 and 5,000 miles on it since then. |
brant |
Mar 28 2016, 02:17 PM
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#8
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914 Wizard Group: Members Posts: 11,625 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
the "big bore" is not an issue. Both djet and ljet can support up to 2.4 liters (as far as I have tested) What camshaft did you put in? Specific number and manufacturer. Rich Just heard back from previous owner, It still has the original cam, all he did was a big bore slip in barrel no block mods completely went through heads guides and seals and check for warp and cracks. Just head work. It was $460 back in 2005 or 2006 and has only had between 2,000 and 5,000 miles on it since then. you should be able to go back to a stock style fuel injection you will want to use an Air fuel meter to tweek your MPS mixture once its running and add a bit more fuel than is stock for a 1.7 to compensate for the big bore. the 1.7 djet parts are going to be cheaper than the 2.0 ones... but either could work with a little tweeking. |
r_towle |
Mar 28 2016, 02:35 PM
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#9
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
(IMG:style_emoticons/default/agree.gif)
Using an Air Fuel meter will be helpful to make sure you are not too lean. You can change a few things if required. You can get 2.0 liter injectors while using 1.7 liter everything else. You can put a resistor inline with the CHT to increase the fuel over the entire range of the system. Both of these may help you easily do the 1911 you have to do. Rich |
TheCabinetmaker |
Mar 28 2016, 04:28 PM
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#10
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I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
I missed fourth gear on a downshift and ended up in second coming off afreeway on ramp in my original 73 1.7 with only a few thousand miles in 1974. Toasted one piston. Installed an npr big bore kit to make it a 1911. I put over 300,000 miles on that engine with the original unmodified djet. That little 1.7 ran perfect. Put the djet back on and drive with a big grin!
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porschetub |
Mar 29 2016, 01:42 AM
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#11
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Advanced Member Group: Members Posts: 4,701 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
the "big bore" is not an issue. Both djet and ljet can support up to 2.4 liters (as far as I have tested) What camshaft did you put in? Specific number and manufacturer. Rich Just heard back from previous owner, It still has the original cam, all he did was a big bore slip in barrel no block mods completely went through heads guides and seals and check for warp and cracks. Just head work. It was $460 back in 2005 or 2006 and has only had between 2,000 and 5,000 miles on it since then. The slip in big bore kits have caused issues,the most important part of the seal to head and barrel is compromised by a limited sealing face on the barrel,it will leak sooner than later. Sorry but that's what happens ,had the heads been opened up and to a correct size with the right kit the issue isn't there,many on here will agree and have great running motors as a result. |
Matty900 |
Mar 29 2016, 09:54 AM
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#12
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Senior Member Group: Members Posts: 1,269 Joined: 21-February 15 From: Oregon Member No.: 18,454 Region Association: Pacific Northwest |
(IMG:style_emoticons/default/agree.gif) Using an Air Fuel meter will be helpful to make sure you are not too lean. You can change a few things if required. You can get 2.0 liter injectors while using 1.7 liter everything else. You can put a resistor inline with the CHT to increase the fuel over the entire range of the system. Both of these may help you easily do the 1911 you have to do. Rich Thanks Richard. Do you know where I can find more how info on this? |
Matty900 |
Mar 29 2016, 09:57 AM
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#13
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Senior Member Group: Members Posts: 1,269 Joined: 21-February 15 From: Oregon Member No.: 18,454 Region Association: Pacific Northwest |
I missed fourth gear on a downshift and ended up in second coming off afreeway on ramp in my original 73 1.7 with only a few thousand miles in 1974. Toasted one piston. Installed an npr big bore kit to make it a 1911. I put over 300,000 miles on that engine with the original unmodified djet. That little 1.7 ran perfect. Put the djet back on and drive with a big grin! That's exactly what I was hoping for. This was a barn find that has been better than I could have hoped for. Can't wait to get it all back together and start driving it. |
Matty900 |
Mar 29 2016, 10:00 AM
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#14
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Senior Member Group: Members Posts: 1,269 Joined: 21-February 15 From: Oregon Member No.: 18,454 Region Association: Pacific Northwest |
the "big bore" is not an issue. Both djet and ljet can support up to 2.4 liters (as far as I have tested) What camshaft did you put in? Specific number and manufacturer. Rich Just heard back from previous owner, It still has the original cam, all he did was a big bore slip in barrel no block mods completely went through heads guides and seals and check for warp and cracks. Just head work. It was $460 back in 2005 or 2006 and has only had between 2,000 and 5,000 miles on it since then. The slip in big bore kits have caused issues,the most important part of the seal to head and barrel is compromised by a limited sealing face on the barrel,it will leak sooner than later. Sorry but that's what happens ,had the heads been opened up and to a correct size with the right kit the issue isn't there,many on here will agree and have great running motors as a result. The guy who did this to the car has built lots of sand rail engines to race on the dunes and seems to know what he is doing. My only concern is how long it has sat since the work was done. |
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